JPS5874351A - Copper evaporated polyester film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to copper deposited polyester films.

Polyester film, especially polyester film based on polyethylene terephthalate.

Due to its excellent mechanical and electrical properties, it is widely used for electrical insulation purposes. Among these, remarkable progress has been made in the field of electronic devices such as flexible printed circuits (hereinafter referred to as F and PC) and connectors.

Conventionally, in applications such as FPCs and connectors, polyester films laminated with aluminum foil, copper foil, etc., or coated with copper paste, carbon coating, etc. are known. but.

All of these have drawbacks in terms of electrical resistance, foreign matter adhesion, cost, etc.

It is also known that a very thin copper layer is formed on a polyester film by vacuum evaporation or sputtering, and then the thickness of the copper layer is increased by electrolytic treatment. However, these had the drawback that their adhesive properties were not sufficient. On the other hand, in the field of electronic equipment, FPCs, connectors, etc. are often used with low currents of 1 Å or less;

Smaller size and higher precision are desired.

An object of the present invention is to provide a copper-deposited polyester film that has flexibility suitable for FPCs, connectors, etc., and has high adhesiveness between the polyester film and the copper layer.

In order to achieve the above object, the present invention has the following configuration, namely:
A polyester film having a heat shrinkage rate of 0.5% or less when heated to 180°C for 60 minutes in a substantially stress-free state, and a film having a thickness of 2000 mm formed by vapor deposition on one side of the film.
A patent characterized by a copper-deposited polyester film consisting of a copper layer of X to 15,000 λ The polyester film of the present invention is a stretched film with a thickness of 85% or more, and contains conventionally known additions, blends, copolymerization components, etc. It may also be something.

It may also be a composite of two or more types of polyester. It is also coated with flame retardants, etc. It is preferable to use a polyester film that has been heat-treated to reduce the heat shrinkage rate prior to copper vapor deposition, and surface treatments such as corona treatment and adhesive coating may also be performed prior to copper vapor deposition. . The polyester film must have a heat shrinkage rate of 0.5% or less, preferably 0.2% or less. If the heat shrinkage rate exceeds the above values.

The adhesion of the copper layer is reduced, and the flatness of the film is also impaired during the manufacturing process of FPl':C, connectors, etc.

Note that the copper layer in the present invention is formed by normal vacuum evaporation, and its thickness is 2000X to 1SO.
Must be ooX. Copper layer thickness is 2000X
If it is less than 15oooX, the moisture and heat resistance is poor; if it is more than 15oooX, there is a problem in use that uneven vapor deposition occurs in the copper layer and the resistance value lacks uniformity.

The copper-deposited polyester film of the present invention is F'PC.

Although it is preferably used for connectors and the like, it can also be used for other purposes that take advantage of its characteristics.

Next, embodiments of the present invention will be described.

Example A polyethylene terephthalate biaxially stretched film having a thickness of 75 μm that had been subjected to conventional heat setting was further heated to 230° C. with substantially no tension in the transverse direction and 0.063 kg in the longitudinal direction.
After heat treatment for 15 seconds under a tension of /mm2, copper was deposited under high vacuum. Table 1.2 shows the results of using this copper-deposited polyvarnish gel film as an FPC board.

Table 1 shows the results showing the influence of the deposited thickness of copper, and the film used had a heat shrinkage rate of 0.2% at 180°C for 60 minutes.

Table 2 shows the results showing the influence of heat yield of the film at 180°C for 60 minutes.

Table-1 Table-2 (The meanings of each item and symbol in the table are as follows.

Humid heat life = 65℃ / 95% RH / 1000 Hr
The evaluation method for film disappearance is based on electrical properties such as resistance value: Resistance value: Surface resistance value (JIs method) Vapor deposition defects: Vapor deposition suitability, pinholes, unevenness:
Etching speed dimensional stability: Temperature used in the FPC board manufacturing process (permissible dimensional change for each 30 minutes).

Adhesion: Test results using adhesive tape peeling method at room temperature ○ mark: Passed as FPC ∆ mark ni tentatively included ×: Fail

Claims (1)

[Claims] (1) A polyester film having a heat shrinkage rate of 0.5% or less when heated to 180°C for 60 minutes in a substantially stress-free state, and a film having a thickness of 2000 mm formed by vapor deposition on one side of the film. A copper-deposited polyester film consisting of a copper layer of X to 15000X.